1. Field of the Invention
The present invention relates to the grouping of individual cigarettes into "blocks" for subsequent packaging and particularly to the formation of cigarette blocks comprising three rows of cigarettes with the middle row containing one cigarette less than the outer rows. More specifically, this invention is directed to apparatus for reliably and gently assembling individual cigarettes into generally rectangular-shaped groups, these groups being defined by an odd number of rows with an even total number of cigarettes, the apparatus further including means for delivering the assembled group of cigarettes as a unit into downstream apparatus for subsequent wrapping. Accordingly, the general objects of the invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
It is customary to package cigarettes in groups of twenty, such groups typically being comprised of two outer rows having seven cigarettes each and a middle row, wherein the cigarettes are staggered with respect to those in the outer rows, comprising six cigarettes. Apparatus for forming such three row cigarette "blocks" are known in the art. An exemplary such device may be seen from published German Patent Application 3,116,156. In the apparatus of this published German application, subsequent to arrangement of the cigarettes to be packaged into three rows of equal length, one cigarette in the middle row is laterally restrained when the remaining cigarettes are ejected from the block forming device. The restraint of this one cigarette in the middle row is accomplished through the use of a mechanical stop. During movement of the cigarettes which are being ejected as a unitary "block", the contact between the cigarettes being ejected and the cigarette being retained results in friction which may damage the relatively fragile cigarette. Any such damage is unacceptable since the retained cigarette will be included in the next succeeding block which is formed. Additionally, the separating-out of an individual cigarette requires a precisely coordinated and synchronized process. Bearing in mind that the cigarettes are delivered under the influence of gravity to the point where they are arranged in multiple-layer rows, it is possible that one cigarette may move into position more slowly than another. Any such uneven movement will upset the synchronism of the separation transfer procedure and will contribute to the possibility of damage to an individual cigarette. While the possibility of cigarette damage, particularly due to uneven speed of movement, can be reduced by judicious selection of the size of the shafts in which the rows of cigarettes are formed, it is impossible to totally eliminate the possibility of a damaged cigarette. Accordingly, the prior art apparatus must be provided with a mechanism which halts the production line when the retained cigarette is subjected to a relatively large, and thus potentially damaging, force. Interruptions in the packaging process resulting from halting the block forming apparatus are, of course, very undesirable due to the "ripple effect" such interruptions have on various other devices such as, for example, the devices which supply the wrapping material.